These proposed studies in ewes are designed to obtain information on the role of the hormones responsible for control of oviductal muscle activity and the resultant effect of muscle contractions on gamete transport. The serum hormone concentrations of LH, estrogen and progesterone as determined by validated radioimmunoassays will be compared quantitatively with: 1) the rate and amplitude of oviductal contractions; 2) the time of ovulation; and 3) the rate of cumulus mass transport in the intact unanesthetized ewe. Instrumental techniques using optoelectronic transducers will be employed for the chronic monitoring of oviduct contractions and for detecting the presence and transport of the cumulus mass. Emphasis will be placed on observing and measuring the oviduct contractile rate, the propagation velocity of the peristaltic (anti-peristalic) contractile wave and the segmental transport velocity and ampullary transport time of the cumulus mass. The physiological experiments, to be conducted in three phases, include: 1) relating the circulating hormone levels of LH, estrogen and progesterone to the time of ovulation and oviduct muscle activity in the normal cycling ewe; 2) determining the effect of a synthetic LH-RH/FSH-RH analog on the time of ovulation, oviduct motility and serum LH, estrogen and progesterone concentrations in anestrous ewes, and 3) determining the effects of exogenous 17-beta estradiol and progesterone on oviduct motility in anestrous ewes. Increasing our knowledge of the reproductive process at the oviduct level may provide valuable information for explaining how steroid contraceptives which do not block ovulation are effective in preventing pregnancy.